Friday, August 9, 2013

How To Clean RV and Camper Trailer Rooftop Air Conditioner (AC) Coils

Merely keeping the filter clean in your rooftop RV AC is not enough. In order for the AC unit to continue to operate efficiently and last a long time the coils must be cleaned every few seasons. The condenser and evaporator coils will eventually become clogged with dust and debris, no matter if you faithfully clean the filter on your rooftop AC unit. Cleaning the coils is a relatively easy task which anyone with basic tools can perform by following these simple steps.


Be sure the AC unit is unplugged from the power source by turning the breaker off or unplugging the RV from the shore connection.


Make sure your RV roof is strong enough to support your weight by using plywood or wide boards if the roof is not constructed to walk on. Remove the nuts holding the protective shroud in place and carefully remove the shroud from the AC unit. Place the shroud aside until the coil cleaning process is completed.


There are especially made solutions just for cleaning AC coils which will make your job much easier, but if don’t wish to purchase one of these you can use certain household products such as 409, or other strong grime cleaners. Some of the commercial coil cleaners do not require using a shop-vac to assist clean-up like the household products normally do.

Spray the coil cleaner on both the evaporator and condenser coils and let soak about 15 minutes or so. You can use a water hose with sprayer attachment to gently blow out the debris from the coils but try not to let the water hit the electric connections directly. Covering these electrical areas with plastic bags will help prevent  moisture from entering the electronics areas.  Don't worry if some areas get wet a little because they are made to resist the elements.


If you have access to a wet/dry shop-vac you can use it to gently remove the excess moisture from the coils. It may be necessary to repeat Step-3 several times to thoroughly clean very dirty or badly clogged coils. After the cleaning process is completed, let the unit thoroughly dry for several hours until the unit is completely dry. The use of a fan to dry the coils will speed this process immensely.


Replace the AC shroud after the AC unit is thoroughly dry, reconnect the electrical power, and the unit should be good to go.  Clean the coils every few camping seasons, or more often if the RV is used year round.  Enjoy your RV rooftop AC unit and keep it clean and cooling properly


Thursday, March 15, 2012

RV AC Repair and Troubleshooting and RV Air Conditioner Maintenance Tips

Today's efficient rooftop RV air conditioners are made to provide many years of comfortable cooling as most are used during the hottest part of the year. If maintained properly, an  AC is normally trouble free except for changing or cleaning the filter regularly.

But like all appliances, an AC unit occasionally requires cleaning or even repairs in some cases. The following tips are intended to assist a travel trailer or motorhome owner to clean or troubleshoot any RV AC problems you may encounter, to repair the AC unit, or find parts for repairs needed.

Common RV AC problems will be addressed as will be the solutions. The questions addressed are actual queries to me from RV owners concerning rooftop AC problems as are the solutions the owners reported. I hope you find this article helpful and feel free to pose your own questions.

How An RV Air Conditioner Works

The main parts of a rooftop air conditioner consists of a sealed compressor which pressurizes and circulates freon though two coils to not only remove any heat from the air circulating through the interior, but to exhaust this same heat to the outside of the RV itself.

The AC fan motor operates a squirrel-cage type fan to pull the cool air through one of the coils and, on the same shaft, a regular type propeller fan to blow the hot air through the other coil so it will be exhausted directly outside of the AC unit.

Both compressor and AC fan motor  utilize a capacitor to boost the power of each on start up to prevent the electrical circuit from overloading and tripping a breaker.  Your RV AC unit may have only one capacitor to start and run both fan and compressor, or each may have a separate capacitor.

The remaining items consist of the thermostat-either wall mounted or in the unit itself-a power switch, and various relays and circuit boards.  These will be discussed later in the article.

RV Air Conditioner Maintenance Tips

Cleaning the RV Coils

Perhaps one of the most common AC problems experienced by owners is caused by having dirty coils in the unit.  The coils-similar to an auto radiator- must be clean enough to allow the cool and hot air to pass easily through the small opening in the coils.

After several seasons of use, these coils will begin to gather dust and other debris in the coil openings causing the efficiency and cooling properties of the AC unit to be adversely affected.  Seasonal cleaning with a special coil cleaner will make a great difference in the temperature of the air being circulated throughout the RV.

When using the coil cleaner, be sure to cover any adjacent painted surfaces to protect them from being stained or damaged.  Coil cleaning products often contain very corrosive chemicals, so keep this in mind.  This procedure is easily accomplished by removing the AC shroud to access both of the coils.  Be sure to cover the vent leading down into the interior to prevent any cleaner or grime from dripping down inside the RV.

Lubricating the Fan Motor   

Some RV  rooftop units utilize oil tubes to easily lubricate the fan motor bearings to keep the shaft turning with the least amount of electrical power possible.  These oil tubes are normally located right above the fan motor seals on each end of the motor.  Simply add a few drops of machine oil occasionally to keep the bearings well lubricated.

Even if yourAC fan motor has sealed bearings with no oil tubes, it is still possible to spray a good quality lubricant around them to provide a bit of future lubrication.  As always, try not to get oil on the coils or other nearby electrical connections.  Be sure to clean up any excess oil after the lubrication process.

Troubleshooting RV AC Problems

The following text contains real questions concerning rooftop A/C problems with the solutions for you to compare with your own particular A/C unit malfunctions.  If you don't find your problem here, please ask in the comment section below and I'll try to address your queries.

The above unit shows a very dirty coil  which caused the unit to not cool efficiently.  A good coil cleaning solution got it back to it's intended cooling capacity.

 Question -Why does the fan run on my rooftop A/C but the air isn't cool?

Answer -The problem may be several different things. The compressor may not be running properly, or not at all.  It is still possible for the fan to operate normally if the compressor is bad.  It is also possible the freon is low in your unit.  A bad starting capacitor could be the culprit too.  The capacitor on many AC units may start both the fan and the compressor.  A malfunctioning thermostat might not allow the compressor to start, so keep this in mind. 

Solution - Normally, if a compressor is trying to run you can hear it when you turn the thermostat to a cooler temperature.  Often the lights will dim if the unit is having trouble starting as it draws more power to enable it to begin the cycle.  A good thermostat will normally click when it sends the signal for the compressor to cycle.  If it doesn't, then your thermostat may be at fault.

If the compressor does indeed run, then more than likely your unit is low on freon.  The freon charge is better left to a qualified repairman as certain tools are required.  if the compressor is bad--this nay be checked with an amp meter to see if the run/start amps are higher than listed on the compressor--then you may be better off to get a new unit.  Replacement is normally cost prohibitive.

Question - How do I check the capacitor if I suspect it is bad?

Answer - Using a digital electrical multimeter, set the selector to the OHM setting and place the probes on the two wiring connection points.  A random number should appear and gradually decrease if the capacitor is good.  If this doesn't happen then replacement of the capacitor is required.

For even more questions and comments check out this highly detailed RV AC Repair article.

Thursday, July 1, 2010

How To Repair RV's, Campers, and Motorhomes

The following RV repair articles will assist you in the many maintenance and repair procedures encountered over the life of your camper trailer or motorhome. Simply click on the links for detailed information on the desired RV repair or maintenance procedure needed. Thanks for visiting my RV Repair Page!

RV Air Conditioner Repair and Maintenance

Motorhome, Camper Trailer, and RV Floor and Roof Repair

RV and Camper Trailer Plumbing and Electrical Repair Links

Other RV, and Camper Trailer Repair Links